2030 International Journal of Food Science and Technology 2011, 46, 2030–2034
Original article The effects of sex and seasonality on the metal levels of different muscle tissues of mature Atlantic blue crabs (Callinectes sapidus) in Mersin Bay, north-eastern mediterranean
Deniz Ayas1* & Yesim Ozogul2
1 Department of Seafood Processing Technology, Faculty of Fisheries, Mersin University, Mersin, Turkey 2 Department of Seafood Processing Technology, Faculty of Fisheries, Cukurova University, Adana, Turkey (Received 9 March 2011; Accepted in revised form 17 June 2011)
Summary The objective of this study was to determine the seasonal and sexual effects on metal levels of lump crabmeat (LCM) and chela crabmeat (CCM) of mature Atlantic blue crabs, Callinectes sapidus, caught in the Mersin Bay, the north-eastern Mediterranean. The findings indicated that the annual ranges of metal levels in the LCM of Atlantic blue crab were as follows: 0.44–0.61 lgCdg)1, 0.30–0.60 lgCrg)1, 0.24–0.52 lgPbg)1, 9.72–43.70 lgCug)1, 39.52–97.26 lgZng)1, 11.97–32.48 lgFeg)1. The annual range of metal levels in the CCM of Atlantic blue crab were as follows: 0.52–1.07 lgCdg)1, 0.24–0.61 lgCrg)1, 0.28– 0.56 lgPbg)1, 22.17–68.09 lgCug)1, 93.92–175.21 lgZng)1, 8.81–19.47 lgFeg)1. Cd, Cu, Zn levels in CCM of Atlantic blue crabs were higher than in LCM, whereas Fe levels were found lower (P < 0.05). Fe metal specifically accumulated in LCM, and Cd, Cu and Zn metals accumulated in CCM. Metals such as Cu, Zn and Fe showed seasonal variations. It was found out that Cu, Zn and Fe levels of muscle tissues of the Atlantic blue crab in spring and summer seasons were higher than in autumn and winter seasons. Keywords Atlantic blue crab, Callinectes sapidus, contamination, metal, season, sex.
in big sea crabs depending on seasons or different muscle Introduction tissue types. For instance, Beltrame et al. (2010) indi- Atlantic blue crab, Callinectes sapidus, is a crustacean cated that there was no relationship between sex, size species which lives in the waters of the western Atlantic and bio-accumulated metals of Burrowing Crab Ocean. This portunid crab species has been introduced (Neohelice granulata) caught from a coastal lagoon in to the Mediterranean waters via blast water. Atlantic Argentina. Olusegun et al. (2009), Go¨kog˘ lu & Yerlikaya blue crabs are commonly distributed in the north- (2003) reported variations in metal levels of different eastern Mediterranean shores in Turkey. muscle tissues of Callinectes species. Beltrame et al. Atlantic blue crab is one of crab species, which have (2010) also reported that concentrations of some metals economic value. Thus, this species is caught both in the (Cd, Cu) in N. granulata showed seasonal changes. world and in Turkey. According to Anonymous (2010), Mature Atlantic blue crabs need moulting to grow up. seventeen and seventy-seven tons of Atlantic blue crabs Taylor et al. (2007) report that samples of cuticle are were caught in 2008 and 2009, respectively, in Turkey. removed from blue crabs, C. sapidus, and within 1 h, The pollution of aquatic environment makes it soft-shell stage begins, following this stage, blue crabs necessary to determine seafood contamination levels. go into paper-shell stage in 12 h and lastly, their hard- Thus, some studies have been conducted on levels of shell stage begins in 7 days after moulting. Following metal contamination of seafood, particularly fish, ceph- moulting, metal levels of blue crabs decrease to a great alopods and crab species, for a long time in Turkey and extent. Bergey & Weis (2007) reported metal elimina- in the world (Olusegun et al., 2009; Beltrame et al., tions during the moulting of carapace in crabs and a 2010; O¨zden, 2010; Ersoy, 2011). reduction in their Cu and Zn metal levels by 3–12% and Although generally, metal level changes in crabs are 8–22%. In a similar study, Benjakul & Sutthipan (2009) not observed related to size and sex, changes can be seen reported decreases by nearly 100% in Cu, Fe and Zn levels of soft shell crabs compared with hard shell crabs. Mersin Bay has been contaminated with the indus- *Correspondent: Fax: (90) 324 3413025; trial, agricultural and domestic wastes. Fertilizers and e-mail: [email protected] pesticides are widely used in agricultural areas in
doi:10.1111/j.1365-2621.2011.02713.x 2011 The Authors. International Journal of Food Science and Technology 2011 Institute of Food Science and Technology Metal level of Atlantic blue crab D. Ayas and Y. Ozogul 2031
Mersin. Besides, until Mersin Waste Treatment Facility Sample preparation was founded, domestic waste was discharged directly to the bay. Furthermore, there are a large number of The crabs were weighed, and some morphometric streams connected to the Gulf of Mersin. Hence, measurements [carapace length (CL), carapace width terrestrial pollution is easily transported to the sea. (CW)] were determined by calliper. Thirty individuals There are a large number of industrial plants such as for each sex group and each season were used. Carap- Mersin port, oil industry, chromium industry, fertilizer aces of all of raw specimens were removed, and the two industry in the city of Mersin. Owing to these reasons, largest portions of meat connected to the swimming legs Mersin Bay is faced with domestic, agricultural and (lump crabmeat – LCM) and meat from chela (chela industrial pollution. As invertebrate sea animals like big crabmeat – CCM) were carefully scraped out with a sea crabs have weak detoxification mechanisms, con- scalpel. All assays were conducted on triplicate samples tamination levels should be kept under control in the of the homogenates. bays, which are vulnerable to pollution. Atlantic blue crabmeat contains high levels of Cu, Metal analysis Zn and Fe (Job et al., 1997; Go¨kog˘ lu & Yerlikaya, 2003; Tu¨rkmen et al., 2006; Olusegun et al., 2009). The LCM and CCM samples (0.5 g dry weight) used for Although there are many studies on the metal levels of metal analysis were dried at 105 C to reach constant Atlantic blue crabs, there is hardly any available weights, and then concentrated nitric acid (4 mL, information about metal levels in Atlantic blue crabs Merck, Darmstadt, Germany) and perchloric acid living in Mersin Bay. Thus, the objective of this study (2 mL, Merck) were added to the samples. Digested was to compare and determine the seasonal and sexual samples were put on a hot plate set to 150 C until all effects on the metal levels of LCM and CCM of mature tissues were dissolved (Canlı & Atlı, 2003). Inductively Atlantic blue crabs in Mersin Bay, north-eastern Coupled Plasma Atomic Emission (ICP-AES, Varian Mediterranean. Model, Liberty series II, Sydney, Australia) was used to determine metals. The metal levels (Cr, Cd, Pb, Cu, Fe and Zn) in samples were detected as lg metal g)1 dry Materials and methods weight. High Purity Multi Standard (Charleston, SC 29423) was used for the determination of the metal Materials analyses. Atlantic blue crabs, C. sapidus, were caught by dip net from Mersin Bay in all the seasons in 2008 on the coast Statistical analysis of north-eastern Mediterranean. The samplings were performed in April (spring), July (summer), October Statistical analysis of data was carried out with the SPSS (autumn) and December (winter). In the fishing proce- 16.0. Duncan test was used to evaluate the seasonal and dure, dip net that had mesh size of 32 mm was used. In sexual effects on metal levels of LCM and CCM of each season, thirty male and thirty female individuals Atlantic blue crabs. were caught and kept in polystyrene boxes with ice. When the crabs were brought to the laboratory, they Results and discussion were still alive. The moulting of crabs was observed in October, and the crabs caught in this month were The average carapace width (CW) was 125.0–185.0 mm semisoft shell crabs. for Atlantic blue crabs (Table 1). In a study carried out
Table 1 Morphological measurements of Atlantic blue crabs in Mersin Bay
CL CW Weight
Season NS X 6SX Min–max (mm) X 6SX Min–max (mm) X 6SX Min–max (g) Sex
Spring 30 71.27 ± 4.13a 63.0–80.0 154.30 ± 9.40a 129.5–170.0 171.67 ± 25.77a 115.27–225.92 $ 30 74.17 ± 3.79a 68.0–80.5 151.65 ± 8.64a 128.0–163.0 191.11 ± 25.58a 154.03–237.93 # Summer 30 69.83 ± 2.53a 66.0–75.0 153.37 ± 6.49a 141.5–162.0 164.86 ± 16.12a 140.16–195.56 $ 30 73.40 ± 4.19a 64.5–79.5 149.90 ± 12.31a 125.0–165.0 233.01 ± 33.21a 165.90–290.78 # Autumn 30 68.97 ± 2.58a 65.0–72.0 149.87 ± 4.32a 145.0–156.0 160.65 ± 12.51a 140.07–175.01 $ 30 77.33 ± 3.64b 73.0–82.0 153.42 ± 9.43a 145.0–169.0 262.06 ± 39.67b 205.11–321.85 # Winter 30 71.45 ± 4.37a 67.0–79.0 153.70 ± 8.91a 142.0–168.0 168.89 ± 20.29a 145.93–203.09 $ 30 79.23 ± 4.29a 73.5–90.5 164.58 ± 12.03a 145.5–185.0 312.68 ± 44.68b 247.19–386.10 #
NS, number of specimens; CL, carapace length; CW, carapace width. Different letters (a, b) in the same columns for each season indicate significant differences (P < 0.05).